tdammers
commented
5 years ago Hi! Thanks for your interest.
The extends tag has been implemented in Ginger, and works just fine, I
use it all the time. There are a few small caveats that may bite you though:
- Unlike jinja, ginger resolves includes and inheritance at compile time, so things like dynamically selecting parent templates do not work (personally I consider this kind of thing undesirable, but it really is a consequence of the architecture rather than a direct design decision). That is, the argument passed to the extends tag must be a string literal.
- In order for extends and imports to work, you need to pass a suitable template loader to the parser. This template loader is a function that takes a raw template name (as written in the extends tag) and runs an IO action returning the template source. Concerns like resolving to the correct directory are left to the implementation of this template loader. If you suspect that this is the issue, it may be worth adding some trace logging to the template loader.
- An extends tag must be the first thing in a template, and the only top-level construct allowed after it is block tags.
Either way, it would be super helpful to get a more precise report of how things fail: do you get any error messages, and if so, what so they say? Or does the template just render something you don't expect? If so, can you paste the offending template, and possibly also the Haskell code that you use on the host side of things?
Re missing features: There is no such list yet, mainly because maintaining it would be a manual effort, and thus prone to human error and lagging (and also, quite frankly, because I'm too lazy to do it). I try to keep the documentation reasonably updated (see https://ginger.tobiasdammers.nl/ for a pretty-rendered version - the markdown sources are in the ginger repo itself though, so you can just as easily browse it on github), but more often than not, features are added without updating all the documentation. We also try to document missing features as github tickets, so if you miss anything, feel free to file one. Because ginger is not 100% compatible with jinja, and probably never will be, and also because ginger offers some things that are not in jinja, it's still a good idea to use ginger's own documentation as a reference. Contributions to the documentation are also very welcome - one thing I'd really love to have, but never got around to, is marking which features are not in jinja, or have different behavior in some cases.
I have the impression that the extend tag (as shown in the documentation is not implemented in ginger 0.8.4.0. Correct? Is there a list of what is implemented or what is missing? would reduce time chasing bugs. Nevertheless, thank you for the implementation!